Heat Conduction in Metal—Ammonia Solutions

Abstract

The thermal conductivity of solutions of lithium, sodium, or potassium in liquid ammonia has been measured as a function of temperature and concentration. The conductivity shows a strong dependence on concentration and rises with increasing concentration to values of 30–60 mW/cm deg at saturation. Pure ammonia has a conductivity of 5 mW/cm deg. Two modes of heat transport, molecular and electronic, may be invoked to interpret the data. The molecular term follows a semiempirical equation often used for insulating liquids. The electronic heat conductivity obeys a Wiedemann—Franz law, with a Lorenz number about 75% of the free‐electron value.